Purchase a package of vegetable seeds. Bean and radish seeds germinate easily and are good choices for seed germination projects. You will also need potting soil, two small plastic drinking cups, glue and a 12-inch square piece of stiff cardboard (corrugated) or foam core board. Either a standalone turntable or a complete record player will be used to exert a lateral force on the seeds. A record album, pencil, glue and scissors will also be needed to set up the experiment.
Lay a 33-1/3 RPM record on the piece of cardboard. With a pencil, trace the outline of the record, forming a circle, and cut it out. Cut or poke a hole in the middle of the cardboard, and place it on the turntable, with the center hole over the turntable's spindle. Glue two small plastic cups onto the cardboard opposite each other and near the outside edge of the circle. Fill each cup with potting soil. Push one seed into the soil in each cup to a depth of about 1/2 inch. Gently pour water into each cup. Two seeds are being planted because not all seeds are viable and will germinate, so this gives a better chance that at least one will make a seedling. Allow time for the glue to dry.
Power on the turntable and set its speed to 33-1/3 RPM (revolutions per minute). The spinning turntable will exert a force on the seeds that is perpendicular to the Earth's force of gravity. Check the cups every day to see if the soil is moist and add a few drops of water if they feel dry. After two or three weeks the seeds should germinate and you may see a stem protruding from the soil.
After about three or four weeks, carefully remove the soil from around the germinated seeds and observe the direction of root growth and stem growth. Determine if the centrifugal force affected the direction of their growth.
Most turntables have speeds of 45 RPM and older models also have 78 RPM. Repeat your turntable project using a higher speed to increase the lateral force on the seeds and make observations.